CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Dividends declared and paid:
Common stock dividends (in dollars per share)	$ 0.515	$ 0.50
Issuance of common stock:
Director compensation (in shares)	6,112	8,007
Stock purchase plan (in shares)	1,477	2,324
Restricted shares, net of forfeitures (in shares)	253,406	259,650
Series E Preferred Stock
Dividends declared and paid:
Preferred stock dividends (in dollars per share)		$ 0.356250
Series F Preferred Stock
Dividends declared and paid:
Preferred stock dividends (in dollars per share)	$ 0.32500	$ 0.32500